Electric furbtaoe



(No Model.) 2 Sheets-Sheet 1. I

W. R. KING. ELECTRIC FURNACE.

No. 562,404. Patented'June 23, 1896,

WITNESSES. v INVENTUH ATTORNEY ANDNEW RGRANAMJHOTOUTND WASHINGYON DC (No Model.) 2 Sheets-Sheet 2. W. R. KING. ELECTRIC FURNACE.

N0.'562,404. Patented June23, 1896.

\IHIHIHIIIHIHI HHlllll!l|lllllllllll N WITNESSES: INVEN TOR Arranlvsr ANDREW BYBRANAWFHUTO-UTNQWASHINGTON] C Lil UNITED STATES PATENT OEEIcE.

IVILLIAM R. KING, OF NEW YORK, N. Y.

ELECTRIC FURNACE.

SPECIFICATION forming part of Letters Patent No. 562,404, dated June 23, 1896.

Application filed February 1,1896. Serial No. 577,661. (No model.)

To aZZ whom it may concern:

Be it known that 1, WILLIAM R. KING, a citizen of the United States, and a resident of the city, county, and State of New York, have made certain new and useful Improvements in Electric Furnaces, of which the following is a specification.

My invention relates to that class of electric furnaces which are intended for the manufacture of calcium carbid and for the reduction of metallic oXids generally. In such furnaces, as heretofore constructed, the producin g capacity is subject to very serious limitations. As is well known in furnaces where the smelting action is obtained by the heat of an electric arc, only such part of the material in the furnace will be smelted as lies within the immediate field of the electric are. This field is, of course, small. Outside of this field the heat generated produces no substantial effect and is virtually wasted.

The attempt has been made to enlarge the effective field of the electric are by increasing the strength of current employed; but this attempt involves serious difficulties and does not produce a sufficient proportional result. Of course the enormously-high potential required in a current which forms an arc of ten or twelve times the effective field of the usual are employed in electric smelting not only involves great danger, but necessitates the constant maintenance of high speed in the dynamo-machine and consequent consumption of power.

I have devised a simple modification of the construction of electricarc smelting-furnaces, which does away to a large extent with these difficulties and dangers and consists in the proper substitution of a multipolar construction for the single arc heretofore employed. I am thereby enabled to arrange in the same furnace using the same hearth, outlet, inlet, feeding device, and other features in common, any reasonable desired number of electrodes and thereby create a corresponding number of arcs, each of which acts as a smelting center for the materials under treatment.

In addition to doing away with the dangers, uncertainties, and other disadvantages of the single-arc furnace, my construction possesses the enormous advantage of doing away with the electrical limitation of the single-arc f on nace. In other words, while it is possible to increase the heat of a single are by increas ing the power and speed of the dynamo-machine or magnetogenerator, it is obvious that there is a practical limit to this electrical increase and that the result produced in smelting must always diminish, as the distance from the center of the arc increases. This is owing, among other things, to the fact that the material smelted is a very bad conductor of heat.

In my improved furnace, I prefer to employ a number of anodes corresponding to the number of electric arcs desired and a single cathode; but other arrangements may be used if preferred.

The distribution of the electrodes in relation to each other at various points in the mass to be treated, regularly or irregularly, may be varied at pleasure; but I prefer a circumferential arrangement around a central feed, as shown in the accompanying drawings, which illustrate what I consider the best form of apparatus embodying my invention.

Figure l is a top plan. Fig. 2 is a vertical section. Fig. is a horizontal section.

Same letters indicate similar parts in the different figures.

F is the furnace, constructed of proper fireproof material and provided with the outlet a for removing the smelted product and with the flue I), through which the volatile matters escape.

G is the hearth, of suitable and desired construction, preferably somewhat shallow and of good conducting material, and is connected to all the negative brushes of the negative generator or dynamo through the post N.

H H H", &c., are the movable carbon electrodes, arranged circumferentially around a central feed, as shown in Fig. 3, and are supported by the triangular frame I, mounted upon the lifting-screws L L, the lower ends of which rest in the socket c on the top of the furnace. The tops of these lifting-screws are provided with sprocket-wheels d, which are connected by the chain 6, so that screws turn in unison and lift the frame I uniformly. Each electrode is removably mounted upon said frame by the shank or rod R R, the top of which fits into the slot ff of said frame.

Each rod is provided at its upper end with a screw-threaded portion g, an adj usting-screw h, and a coiled spring 70. By this means each electrode can be raised or lowered independently of the others to compensate for the differences which may exist in the molecular structure of the various electrodes and consequent differences in wearing away in use. Each of these rods is connected to one of the positive brushes of the electric generator or dynamo through one of the posts P P.

K is the cap or cover of the furnace, appropriately perforated to allow the passage of the rods R R and also the central feed-tube T, which descends a suitable distance into the furnace centrally with regard to the circumferential arrangement of the electrodes H H :H2, 850.

M is the cone or hopper through which the material to be smelted is introduced into the furnace through said tube.

S is a deflector, so arranged at the bottom of the tube T as to scatter the falling material radially and bring it most easily into the center of the fields of the respective arcs.

It is obvious that an electric arc will be established between the lower end of each of the electrodes and the point of least resistance in the hearth below it and that each of these arcs will act as an independent smelting center for the material which comes within its field. By proper manipulation of the liftingscrews and proper adjustment of the individual rods, all of these electric arcs can be maintained in the same degree of activity; and if, by accident, one of the arcs goes out, the action of the other arcs will not be interfered with.

The smelted material as fast as formed is readily accessible and removable through. the outlet at.

The many advantages of this improved multipolar furnace can be readily understood without further description.

I claim 1. A multipolar electric-arc smelting-furnace provided with a number of separate movable electrodes, mechanism for moving said electrodes in unison, whereby the length of the several electric arcs is regulated, feed mechanism, whereby the material to be smelted is fed into said furnace and a deflecting device, whereby the material so fed is brought within the field of each of said arcs, substantially as and for the purposes specified.

2. A multipolar electric-arc smelting-furnace provided with a number of independent movable electrodes, whereby a corresponding number of electric arcs may be produced, mechanism for moving said electrodes in'unison, whereby the length of said arcs may be regulated, mechanism for moving each of said electrodes independently of the others, whereby the length of the corresponding arc may be varied, feed mechanism, whereby the material to be smelted is fed into said furnace and a deflecting device, whereby the material so fed is brought within the field of each of said arcs, substantially as and for the purposes specified.

3. A multipolar electric-arc smeltingfurnace, provided with a central feed, a number of independent movable electrodes arranged circumferentially around said feed and a deflecting device, whereby the material introduced into said furnace is deflected into the field of said electrode, substantially as described and for the purposes specified.

WILLIAM R. KING.

\Vitnesses J. KENNEDY, V. P. PREBLE, Jr. 

